The case of the disappearing colloid cyst.

BACKGROUND: The natural history of colloid cysts is imperfectly understood, controversies remain in defining broad management strategies for incidental colloid cysts. The gradual asymptomatic regression of a colloid cyst has not been reported. CASE DESCRIPTION: We present a unique case demonstrating the clinically at, gradual regression of a colloid cyst over many years. CONCLUSIONS: Gradual regression of a colloid cyst is possible. The philosophical and practical implications of this case on the neurosurgeon's approach to managing patients with colloid cysts are discussed.